code: def clean_underscore():
      # reset the Underscore object after the test, to avoid having state copied across tests
      yield
      Underscore.doc_extensions = {}
      Underscore.span_extensions = {}
      Underscore.token_extensions = {}
  
file_path: spacy/spacy/tests/doc/test_underscore.py
imports: import pytest
  from mock import Mock
  from spacy.tokens import Doc, Span, Token
  from spacy.tokens.underscore import Underscore
label_desc: Use image node_id 1 for calling a global function with example usage: clean_underscore() without return types